This proposal outlines experiments to develop a better understanding of icosahedral RNA virus assembly. It focuses on specific interactions between capsid protein and viral RNA as well as aspects that control recognition, condensation and encapsidation of the viral genome. It addresses the unresolved issue of how multipartite RNA genomes are recognized and packaged into a single virion and it seeks to define the role of cellular parameters in this process. The experimental plan takes advantage of a highly developed model system represented by the icosahedral RNA containing nodaviruses. Nodaviruses are a family of genetically, biochemically and structurally exceptionally well characterized viruses that have proven to be highly tractable for the study of fundamental questions in virology, including particle assembly and packaging of the genome. The [unreadable] specific aims of this project are: (1) to investigate the role of subcellular compartmentalization in the [unreadable] Flock House Virus (FHV) life cycle using biochemical and genetic approaches; (2) to visualize [unreadable] cellular compartmentalization and spatial dynamics during FHV infection by fluorescence microscopy and electron microscopy; (3) to identify mechanistic strategies and molecular elements involved in packaging of the FHV genome and (4) to define the role of FHV coat protein in folding and condensation of viral RNA during assembly. [unreadable] [unreadable]